Re: Samsung DLP HLT6187SX/XAA won't display video

I desoldered some of the caps around the main processor on the board, tested them, found no problems. Trying to determine where the source of the low resistance was, I ended up desoldering everything on the 1.3VB rail, including lots of small ceramic smd caps, the buck converter chip, some diodes, and so on. I ruled out everything but the processor. I decided to clean out all the rosin flux that I had left under that processor throughout the ball grid array from my reflow attempt using some heat and lots of isopropyl alcohol and...

Re: Samsung DLP HLT6187SX/XAA won't display video

Thanks for the reply!

I measured all the voltages from the power supply, and all seems well there except one thing. There is a place where the schematic indicates 16 volts where I measure 18 volts. Is this potentially a problem? I get that same reading even when everything works.

Right now, I have a bunch of caps off the board as I've been testing them, and I had to order a new soldering iron (a Hakko FX-888D to replace my $20 Radio Shack piece of junk!), so I can't test anything at the moment, but I'll...

I'd appreciate any suggestions!

This is an LED DLP TV with no lamp or color wheel. It has big R, G, and B LEDs for the light engine. It has seen regular use since late 2007.

It started taking longer to warm up before coming on. Later, it began doing glitchy things before warmed up. Sometimes, I'd get audio, but no video. Sometimes, the screen would get scrambled with odd patterns and there'd be a loud buzz from the speakers. It would reset itself after a bit. Other times, the audio would be higher pitched, making human voices like The Chipmunks, then lock up, then...

Re: Samsung HL67A750 DLP with bad caps!

It didn't last more than a day. Back to troubleshooting.

Re: Samsung HL67A750 DLP with bad caps!

Well, I finally replaced all the small electrolytic surface mount caps on the mainboard and it works! FINALLY! Now I just need to get it all back together!

Re: Samsung HL67A750 DLP with bad caps!

stanman2242,



No. I replaced all of the aluminum electrolytic caps on both power boards before trying it again. And everything behaved just like before. I didn't have an ESR meter at the time. But when I got one, I tested all the caps I pulled from those boards and roughly half of them had quite high ESR readings. One of them, a mid-sized one (don't remember the specs) had an ESR of about 20 ohms but looked just fine, with no bulging. The five bulged ones also had very low capacitance readings. They were supposed...

Re: Samsung HL67A750 DLP with bad caps!

I've been working on a Samsung HLT6187SX/XAA for some weeks now. For quite a while, it has had problems when first powering on. The green light will blink once per second for a while, then go solid for a bit, then start blinking again. After a while, it might come on and display video but fail to respond to control requests, as if something is frozen. Or sometimes the sound is such that everything is maybe twice the normal pitch, making people sound like The Chipmunks. Other times, the audio is just a loud buzz. Or sometimes, audio is fine,...